Mitsubishi Repair: 1999 Galant hesitation prob, mass air sensor, fuel pressure regulator

Question
I have a 199 Galant LS 4 cyl...after the car has been driven for a while and it has come up to temp and then it is shut off and left for about 10-20 minutes,  when you restart the car and try to drive off it hesitates terribly. I have to put the car in neutral then press down the gas pedal almost all way before it will return to normal operation..it only does it after it has been turned off then on again after it has been warmed up...any ideas

Answer
Frank,
This problem could have several possible causes.  You may have a malfunctioning fuel pump, clogged fuel filter, or faulty fuel pressure regulator.  

Your problem may also be in your ignition system.  Have your alternator, spark plugs, plug wires, and distributor checked.  Excessive heat can cause a lot of interference in the electrical components.  

I have also seen this problem happen when there's an issue with the mass air sensor, exhaust gas recirculation valve, idle air control motor, and throttle body.  All those items deal with your air intake system.  

Because this only seems to happen when your engine is hot, you should also have your cooling system checked.  You may have a faulty temperature sensor (thermostat), which thinks your engine is near overheating, so it will not allow the engine to start or run well until it cools down.  

It's real tough to pinpoint exactly what could be wrong because this problem has such a large number of possible causes.  I'd recommend finding a good mechanic to check all these items.
Good luck!